Auxiliary fireplace heater



May 7,1940. "r. MAIRS AUXILIARY FIREPLACE HEATER Filed July 11. 19:59

x mm TM M my 2 4 u Patented May 7, 1940 UNITED STATES PATENT OFFICE.

4 Claims.

dinary heating furnace, boiler, or other heat-' developing apparatus, and has for its objects, first,.to provide a means connectedto the smoke chimney for extracting the heat of the rising smoke or waste gases therein as it passes through the, device; second, to provide an apparatus for heating the air of a room by means of the hot gases in the chimney; third, to combine said airheating means with an open fireplace; fourth, to provide a suitable control means whereby the apparatus' may be placed in or out of action; and fifth, to provide such an apparatus as will be simple and cheap in construction, permanent in nature, and effective in use.

I attain these and other objects by the devices and arrangements illustrated in the accompanying drawing, in which,

Fig. 1 is a vertical section of my improved auxiliary fireplace heater, taken on the line l-l in Fig. 2; Fig. 2 is a horizontal section thereof taken on the line 22 in Fig. 1; Fig. 3 is a vertical section of a portion thereof taken on the line 33 in Fig. '2; Fig.4 is a horizontal section of a variation of my invention in which the heat from the chimney is used in a room without a fireplace; and Fig. 5 is a vertical section thereof.

Similar numerals of reference refer to similar parts throughout the several views.

Referring to Fig. 1 of the drawing, it will be seen that the furnace, boiler, or other heat-generating apparatus 6 is located, as is customary, in the basement of the building, and is provided with a smoke pipe 1 which leads therefrom through the chimney walls 8 and into the vertical smoke flue 9 thereof. It will also be seen by Figs. 2 and 3 that this flue 9 is positioned towards the rear and to one side of the fireplace located on the floor above.

In the preferred form of my invention, the fireplace is one of the type known as heat circulators which, normally, are provided with a hearth l9 having a metal back plate II and metal side plates l2, both adapted to transmit theradiated and conducted heat from the fire on the hearth in to the air chamber l3 surrounding the rear and sides of the hearth. The gases of combustion eventually pass to the chimney flue It by the passage 15. This air chamber 13 is connected to the room I6 by means of suitable cold air passages ll positioned, usually, near the floor or base of the hearth ID. The air in the said space I3 is therefore heated by the fire on the hearth I6 and passes out into the room l6 by means of suitable hot air passages l8; The air chamber [3 is provided with a back closure plate l9 and side closure plates 20. Inmy apparatus the side closure plates 29 are connected to outer enclosing plates 2| which form a second confined chamher which I have designated as the smoke chamber 22.

The chimney flue 9 is provided with an opening 23 through the wall thereof and connecting with an opening 24 through the said outer plate 2| of the smoke chamber, near the bottom thereof, and also the said flue 9 is provided with a second or upper opening 25 connecting with an upper opening 26 through the said outer plate 2!. The smoke chamber 22 is provided with a bafile plate 21, positioned between the lower opening 24 and the upper opening 26 (Fig. 3) to force the hot gases from the chimney flue 9 to circulate within the smoke chamber and to contact as large an area of the back and side closure plates I9 and 29 as is practical.

A pair of control plates or valves are mounted in the wall openings 24 and 26 (Fig. 3). The lower valve plate 28 is hinged at its upper end 29 to the plate 2| and extends into the flue 9 through the opening 23, while the upper valve plate 30 is hinged at its lower end 3| to the said plate 2| and also extends into the flue 9 through the opening 25. These two plates 28 and 30 are adapted to substantially close their respective openings or to swing into the fiue 9 to divert the hot gases flowing upward therein into the smoke chamber 22 and then guide them from the said smoke chamber 22 into the flue 9 again.

In order to facilitate the operation of these two plates 28 and 30 they may be connected together in such manner as to balance each other by providing the upper plate 30 with an arm or lever 32 and connecting said lever 32 with the complementary position on the lower plate 28 by means of a link 33. Since the link 33 connects the two plates on opposite sides of the respective hinges 29 and 3!, and since the points of connection are complementary to each other, or equally distant from the said hinges, it is evident that they will balance each other in all positions and that the operation of one will cause the other to move equally in the opposite direction. Suitable operating means, not shown, may be provided whereby they may be controlled from the room A modified form of my invention is shown in Figs. 4 and 5 in which the heat of the waste gases flowing up the chimney flue is extracted and used to heat a room without any fireplace. In this case the chimney flue 9 is cut and a metal radiator chamber is inserted therein. This radiator chamber comprises an inner open-ended smoke chamber 5%) through which the smoke and hot gases in the chimney pass upward. The walls SI of this chamber may be provided with a series of inward extending fins or plates 52 secured thereto. These fins 52 are surrounded by the flowing hot gases and conduct the heat therefrom to the walls 5i, thus increasing the area of the surfaces exposed to the heat. The walls 5! of this smoke chamber 58 are surrounded by a closed metal air chamber 53, having a cold air inlet grid at the'base and a hot air outlet grid 55 at the top. The air inlet 54 is preferably positioned at the floor of the room 56, thus taking the cold air therefrom and. delivering warm air to the room. at a higher level.

It is, of course, understood that many variations may be made in the details of my improved auxiliary heater without departing from the spirit of my invention as outlined in the appended claims, and that the words and terms used in the specification and claims have been selected for convenience of description and are to be given the most generic meanings consistent with the present art.

Having, therefore, described my invention,

what I claim and desire to secureby Letters Patent, is:

1. An auxiliary heater comprising an open fireplace having metal walls; an air chamber having metal walls, at least one such wall being common to said air chamber and said open fireplace; air

inlet and outlet passages to said air chamber; a

flue in which hot waste gases are passing; a

smoke chamber having metal walls, at least one wall of which is common to said smoke chamber and said air chamber; and passages connecting the lower and upper portions of saidsmoke chamber to said flue and forming inlet and outlet connections for the hot gases therein. 7

2. An auxiliary heater as set forth in claim 1, together with means directing the hot gases to pass from said flue through said smoke chamberand. return to said flue.

3. An auxiliary heater as set forth in claim 1, together with controllable means directing the hot gases to pass from said flue through said smoke chamber and return to said flue.

4. An auxiliary heater as set forth in claim 1, together with a bafile plate in said smoke chamber and positioned between the upper and lower passages and adapted to force the smoke to circulate in said smoke chamber in passing from the inlet" to the outlet passages thereof.

THOMAS MAIRS. 

